You can Tag your friends or yourself in a Facebook photo, You can also tag someone that doesn't have a Facebook account. Follow this post to know how to do that.1- Go to the photo and click on Tag Photo button2- Click on the part in the photo you want to tag then enter your friends name or (their email if they don't have a Facebook account) and press Enter3- Click Done Tagging when you finish Tagging.

When you tag someone, they'll be notified. Also your friend can tag anyone in your photo and it will be visible to the audience you selected plus friends of the tagged person.